PubMed Health⌕ Search

Biomedical subjects

H Grossniklaus

Publications and source records attributed to H Grossniklaus.

17 recordsLinked to original sources
PubMed2004

The Zimmerman-McLean-Foster hypothesis: 25 years later.

It is now 25 years since the publication of the landmark article by Zimmerman, McLean, and Foster, in which they cast doubts on the benefit of enucleation, which was the prevailing management of choroidal melanoma at that time. Over the past 25 years several advances have been made in the management of uveal melanoma. Research in the pathobiology of cancer metastasis in general and uveal melanoma in particular has also provided new insights. In this review, the Zimmerman-McLean-Foster hypothesis is explored in the light of current clinical, epidemiological, statistical, and experimental evidence.

Brachytherapy↗
PubMed2001

Interleukin-18 expression and modulation in human corneal epithelial cells.

PURPOSE: The interferon-gamma-inducing factor Interleukin-18 (IL-18) is a recently described cytokine that appears to have multiple important pro-inflammatory effects including the induction of interferon-gamma (IFN-gamma) by activated T-cells. The expression of IL-18 by human cornea has not been previously reported. In the present study, we examine the possibility that human corneal epithelial cells are capable of producing this leukocyte-activating factor which may play an important role in IFN-gamma-dependent inflammation responses in the cornea. METHODS: Northern blot analysis and ELISA were used to investigate the in vitro expression of IL-18 mRNA and protein respectively in primary (HCEC) and transformed human corneal epithelial cells (HCET). To determine if IL-18 expression was modulated by pro-inflammatory mediators, cells were treated with lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA) or synthetic double stranded RNA (poly dI : dC). IL-18 bioactivity was determined in a leukocyte interferon-gamma induction assay and IL-18 was immunolocalized in whole human cornea by immunohistochemistry using a specific anti-IL-18 antibody. RESULTS: IL-18 mRNA and bioactive protein was constitutively expressed by human corneal epithelial cells and upregulated by PMA, LPS and poly dI : dC. The constitutive expression of IL-18 protein immunoreactivity was also demonstrated in the epithelial cells of whole human cornea tissue. CONCLUSIONS: This is the first study demonstrating that corneal epithelial cells are capable of producing the IFN-gamma inducing factor IL-18. Increased bioactive corneal IL-18 production can be induced by a number of pro-inflammatory agents and may play an important role in initiating gamma-interferon-mediated inflammatory responses in the cornea.

Blotting, Northern↗
PubMed1999

Surgical management of subfoveal neovascularization in children.

OBJECTIVE: To report the authors' clinical experience with submacular surgery for subfoveal membranes in children and to evaluate the histopathologic findings of membranes in children with various etiologies of choroidal neovascularization. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Twelve eyes of 12 consecutive children with subfoveal choroidal neovascularization treated by vitrectomy and excision of the choroidal neovascular complex. INTERVENTION: Vitrectomy, excision of the choroidal neovascular complex, and air-fluid exchange. MAIN OUTCOME MEASURES: Visual acuity and recurrence of choroidal neovascular membrane. RESULTS: Preoperative visual acuities ranged from 20/60 to 20/800 (median, 20/300). Postoperative visual acuities ranged from 20/25 to 20/400 (median, 20/80) after an average follow-up of 20 months (range, 7-62 months). Ten of 12 eyes improved from immediate preoperative visual acuity, and four eyes developed recurrence of neovascular membranes over a mean follow-up of 18 months. Histopathologic examination of six excised membranes showed that the most common components of the membranes were retinal pigment epithelium, fibrocytes, vascular endothelium, and collagen. CONCLUSION: Selected eyes of children with subfoveal neovascular membranes and no evidence of membrane regression may benefit from submacular surgery. The histopathologic findings were similar to adult choroidal neovascularization not associated with age-related macular degeneration.

Adolescent↗
PubMed1997

Tumors of the cornea and conjunctiva.

This article reviews the literature published in 1996 regarding conjunctival and corneal tumors. There is an increased incidence of squamous cell carcinoma of the conjunctiva in patients with HIV infection, especially in young individuals and Africans. Presumed causative factors for conjunctival squamous cell carcinoma include ultraviolet light, HIV infection, human papillomavirus and other unknown factors. Metastatic tumors to the conjunctiva appear at an advanced stage of the disease, and metastases to the conjunctiva are a poor prognostic sign for survival. Reviews of premalignant lesions of the conjunctiva, including diagnosis, treatment, and recurrence, are discussed. Spindle cell and mucoepidermoid variants of squamous cell carcinoma of the conjunctiva have a worse prognosis for intraocular extension compared with usual conjunctival squamous cell carcinoma.

Conjunctival Neoplasms↗
PubMed1996

Evaluation of a delivery system providing long-term release of cyclosporine.

OBJECTIVES: To examine the clearance of cyclosporine after intravitreal injection and to assess the kinetics and toxic effects of an intravitreal device that provides sustained delivery of cyclosporine. METHODS: Rabbits were divided into two groups to evaluate (1) the elimination kinetics after 1-microgram and 10-microgram intravitreal injections of cyclosporine and (2) the levels produced after implantation of a device that contained cyclosporine over 6 months. The toxic effects of the intravitreal device over 6 months were assessed in rabbits and cynomolgus monkeys. RESULTS: After the 10-microgram injection, the half-life was longer (10.8 hours vs. 4.2 hours) and the distribution volume was smaller (1.7 mL vs 3.2 mL) than after the 1-microgram injection. This difference can be attributed to saturable partitioning of the drug. The device resulted in a vitreous concentration of approximately 500 ng/mL throughout the study period. In the rabbit it resulted in reversible lens opacification and decreased b-wave amplitude. This toxic effect was not detected in the monkey. CONCLUSIONS: The device produces sustained intravitreal levels of cyclosporine. Although it was associated with reversible toxic effects in the rabbit, it was well tolerated in primates. Sustained-release implants are a promising new treatment for chronic uveitis.

Animals↗
PubMed1996

Comparative treatment of experimental Staphylococcus aureus endophthalmitis.

PURPOSE: To compare treatment strategies for Staphylococcus aureus endophthalmitis, we created an animal model in an aphakic rabbit eye and tested six different approaches to treatment. METHODS: Rabbit eyes were rendered aphakic, and three weeks postoperatively, S. aureus organisms were injected into the vitreous cavity. One group was maintained as a control. Twenty-four hours after bacterial injection, six different treatment groups were created for comparison. Clinical inflammation scores, culture results 48 hours after treatment, histopathologic gradings, and development of total corneal opacity three weeks after treatment were assessed. RESULTS: Injection of vancomycin hydrochloride into the vitreous cavity was more effective than injection of cefazolin sodium (P = .01) in reducing the percentage of eyes that had positive culture results and also resulted in lower inflammation scores. Vitrectomy plus injection of either antibiotic was more effective than injection of the same antibiotic alone in reducing culture-positive results and reducing clinical inflammation scores. addition of systemic corticosteroids to intravitreal antibiotic injection did not improve any measure of outcome. Vitrectomy and injection of intravitreal vancomycin was the most effective strategy to sterilize the vitreous cavity, resulting in the lowest inflammation scores and the smallest percentage of eyes with opaque corneas. CONCLUSION: In an animal model of S. aureus endophthalmitis, the combination of vitrectomy and injection of intraocular vancomycin was the most effective strategy for rapidly controlling the infective process and improving the outcomes measured three weeks after treatment.

Animals↗
PubMed1995

Climatic proteoglycan stromal keratopathy, a new corneal degeneration.

PURPOSE: To characterize a previously undescribed corneal disorder, climatic proteoglycan stromal keratopathy. METHODS: We prospectively characterized the disorder in 58 eyes of 29 patients (ages 41 to 84 years) at the El Maghraby Eye Hospital, Jeddah Saudi Arabia. Light and transmission electron microscopy were performed on six corneal specimens. RESULTS: Clinical criteria for the diagnosis included a central, horizontally oval, corneal stromal haze with a ground glass appearance, a uniform or lamellar pattern, greater extent anteriorly and involvement of 50% to 100% of stromal thickness. It occurred bilaterally but sometimes asymmetrically. Density varied from mild to moderate and seldom decreased visual acuity. Sixteen (28%) of 58 corneas had additional degenerative lesions (spheroidal degeneration, mild calcific band keratopathy, and Salzmann's nodular degeneration). Refractile stromal lines or posterior white dots were present in six (10%) of 58 eyes. Videokeratography in 11 (29%) of 38 eyes demonstrated flat areas that overlay the stromal haze. Pathologic analysis demonstrated focal intracellular and extracellular deposits of excess proteoglycans. One specimen showed amyloid. We postulate that climatic factors play a pathogenic role because the disorder occurs in individuals who were exposed to the sunny, dry, dusty environment of the Middle East and because other corneal degenerative disorders were present concomitantly. CONCLUSIONS: Climatic proteoglycan stromal keratopathy is a corneal degeneration that appears as an oval, central, gray, ground-glass haze associated with central corneal flattening on videokeratography and as excess proteoglycans on histologic examination. It seldom severely decreases visual function.

Adult↗
PubMed1995

Inflammatory pseudotumor of the eyelid.

We present three patients whom we believe developed idiopathic inflammatory pseudotumors confined to the eyelid tissues with no evidence of orbital involvement. All three patients were misdiagnosed initially as having lesions of an infectious etiology. All three patients responded completely and rapidly to oral steroid therapy after the correct diagnosis was confirmed by biopsy. We believe that pseudotumor of the eyelid is a distinct subtype of idiopathic inflammatory pseudotumor.

Administration, Oral↗
PubMed1995

Neonatal lensectomy and intraocular lens implantation: effects in rhesus monkeys.

PURPOSE: To compare the effects of a lensectomy with and without intraocular lens (IOL) implantation on a neonatal rhesus monkey eye. METHODS: A lensectomy and anterior vitrectomy was performed on 75 monkeys during the first 16 days of life; 21 of these monkeys also had an IOL implanted into the posterior chamber. The eyes were examined at regular intervals using biomicroscopy, applanation tonometry, and ophthalmoscopy. RESULTS: The pseudophakic monkeys were studied until they were 92.5 +/- 5.8 weeks of age and the aphakic monkeys until they were 80.4 +/- 5.7 weeks of age. Pupillary membranes (100% versus 55.5%; P < 0.01) and lens regeneration into the pupillary aperture (28.6% versus 5.6%; P = 0.02) occurred more often in the pseudophakic than the aphakic eyes. As a result, the pseudophakic eyes required more reoperations than the aphakic eyes to keep the visual axis clear (P < 0.01). There was not a significant difference in the incidence of ocular hypertension between the pseudophakic and aphakic eyes (9.5% versus 12.7%; P = 0.34). Pupillary capture of the IOL optic occurred in 52% and haptic breakage in 33% of the pseudophakic eyes. All of the eyes with broken haptics had a prominent Soemmerring's ring varying in maximum thickness from 0.6 to 2 mm. Nine of the haptics from the seven eyes with broken IOLs had eroded into the iris, two into the ciliary body, and one into the anterior chamber. CONCLUSIONS: Implanting an IOL into a neonatal monkey eye after a lensectomy and anterior vitrectomy increases the likelihood of a reoperation being necessary. Haptics frequently erode into the iris and ciliary body and may break because of stress placed on the optic-haptic junction by forward movement of the IOL.

Animals↗
PubMed1990

Sclerosing syringoma.

Syringoma, a benign sweat gland tumor which may occur in the eyelid, commonly presents as multiple lesions in young women. We had an unusual case of a sclerosing syringoma found as a single lesion in the lower eyelid of a man.

Adenoma↗
PubMed1987

Nonsimultaneous primary choroidal and cutaneous melanomas. Report of a case.

The authors report a patient with nonsimultaneous choroidal and cutaneous melanomas. The patient did not display the dysplastic nevus syndrome phenotype, and there was a negative family history for cutaneous or uveal melanomas. This sporadic case might suggest a common etiologic factor in the pathogenesis of multicentric malignant melanomas.

Choroid Neoplasms↗
PubMed1986

Acute monocytic leukemia presenting in the eyelid. An immunohistochemical and electron microscopic study.

A 28-year-old woman was evaluated for a firm subcutaneous nodule of the left upper eyelid. Results from the examination showed multiple red to brown subcutaneous nodules on her upper extremities and thorax. An excisional biopsy specimen showed the nodules to be cutaneous involvement of acute monocytic leukemia. Acute monocytic leukemia should be considered in the differential diagnosis of a subcutaneous nodule in the eyelid.

Adult↗
PubMed1983

Computed axial tomography in ophthalmology.

Diagnostic accuracy of computed axial tomography (CT) of the eye and orbit is limited by resolving power and interpretation. Indiscriminate use of the scan is limited by radiation exposure and cost of the modality. The use of CT should be reserved in the ophthalmologist's supply of diagnostic modalities and be used as part of an orderly, logic scheme of diagnostic testing. The scheme proposed advises ordering a B-mode ultrasound before CT.

Adult↗
PubMedDate not supplied

Infantile lensectomy and intraocular lens implantation with long-term follow-up in a monkey model.

PURPOSE: To report the long-term clinical and histopathologic findings in infant monkeys following a lensectomy and intraocular lens (IOL) implantation using two different surgical techniques. METHODS: A lensectomy and IOL implantation was performed on the right eye of 10 infant monkeys. A posterior capsulotomy was performed using a limbal approach in 5 monkeys (Group 1), and a pars plana approach in 5 other monkeys (Group 2). The residual refractive error in the pseudophakic eye was then corrected with a contact lens and the fellow eye was occluded for 70% of the daylight hours. The monkeys were then examined at regular intervals for 2 to 4 years. Visual acuity was assessed using operant testing and sweep visual evoked potentials (VEPs). At the end of the study, the pseudophakic eyes were studied histopathologically. RESULTS: The only complications that required reoperation were diaphanous fibrin membranes on the lens optic (n=10) and lens reproliferation into the pupillary space (n=5). The visual outcome was similar in Groups 1 and 2, with better acuities in the phakic eyes compared with the pseudophakic eyes. A higher percentage of both haptics were found in the capsular bag for the monkeys in Group 2 (n=3) than in Group 1 (n=1). CONCLUSIONS: Although haptic placement was superior using a pars plana approach to perform the primary posterior capsulotomy, no clinically discernable difference was noted in IOL centration between the monkeys undergoing a limbal versus a pars plana posterior capsulotomy and no difference was noted in the visual outcome.

Animals↗
PubMedDate not supplied

Increased corneal scarring after phototherapeutic keratectomy in Fuchs' corneal dystrophy.

PURPOSE: A 63-year-old female with Fuchs' endothelial corneal dystrophy, stromal edema and subepithelial scarring was inappropriately treated with phototherapeutic keratectomy, leading to a central focal circular corneal scar and decreased visual acuity that required penetrating keratoplasty. METHOD: The host corneal button was bisected and fixed in 10% formaldehyde and in glutaraldehyde immediately after its removal. RESULTS: Light microscopy demonstrated a central area of absent Bowman's layer with a thin layer of subepithelial fibrosis, stromal corneal edema, and thickened Descemet's membrane. CONCLUSION: Correct estimation of differential ablation rates of tissue and shallow, repeated ablations followed by slit-lamp microscopy and/or videokeratography help prevent over-treatment.

Cicatrix↗